It is imperative to find ways to improve retention in care and boost ART adherence in sub-Saharan Africa where adherence rates have been found to decline over time and where treatment options such as second-line treatment are very limited. Successful interventions need to take the resource constraints in these countries into account, be able to bolster adherence over an individual's life-time, and can be combined with other proven strategies. A promising such tool is the Rewarding Adherence Program (RAP) suggested in this proposal, i.e. the use of small prizes for healthy HIV-related behavior allocated by a drawing. The intervention is targeted at increasing the motivation of mature clients who have been on ART for several years through the added benefit and joy of potentially winning a prize, thereby attempting to overcome the treatment 'fatigue' that can develop in the context of mundane, daily pill taking over the course of life-long treatment. Insights from behavioral psychology, in particular Operant Conditioning, suggest that the use of variable rewards results in reinforcement of behavior that is particularly resistant to extinction, i.e. increased adherence over long time periods. Phase 1 of the proposed study will use qualitative interviews to ensure adaptation of the intervention to the local context, and determine suitable intervention parameters. Phase 2 will pilot test RAP in a randomized controlled trial for clients who have been on ART for at least 2 years and who show adherence or retention problems, as it is these clients for whom treatment fatigue is potentially a problem. All 80 clients will receive MEMS caps to record adherence and five study assessments over 12 months (at baseline and every 3 months thereafter). For the intervention group, timely clinic attendance and drug refill over the past month will determine the number of entries they receive for winning a monthly prize. Given optimal adherence, each participant can expect to win a prize twice over the study period. Phase 3 of the study adapts RAP to address limitations identified in Phase 2 and applies it to the control group for six months. In addition, qualitative interviews will be conducted with providers, implementers, and study participants to learn about implementation difficulties and areas for future improvement. Study findings will inform the design parameters of a larger, more rigorous evaluation in an R01 application.